So the SM at HiFi Engine isn't the best scan that I've seen but it's (just) good enough to read everything on the schematic.
There are a lot of elcos in this amp and I counted 30 coupling caps that are directly in the signal path.
In the CD Buffer:
C103, 106, 129 and 130 = 10µF/16v.
Tuner & Tape 1 Buffer:
C109, 112, 132, 133, 113, 116, 136 and 137 = 10µF/16v.
Volume Amp:
C301, 302, 315 and 318: 10µF/16v.
Tone Amp:
C401, 402 = 4.7µF/25v.
C407, 408 = 22µF/16v.
C421, 422 = 1µF/50v.
C429, 430 = 100µF/16v.
Phono EQ Amp:
C144, 149 = 10µF/25v.
C153, 156 = 22µF/16v.
Pre / Power Amp:
C505, 511 = 2.2µF/50v.
Considering that the film caps are a lot more expensive than elcos you will probably only want to use them where it counts the most for your most often used inputs. If you use mostly CD for instance and not phono I'd use film caps only in the CD buffer, Volume Amp and Pre/Power Amp sections
if/where they will fit. The 10µF MKS2 are pretty large and you will have to measure for space.
Nichicon KL are probably the most cost effective quality cap to use where you don't use film and they are low leakage = low noise.
I'm only talking about the signal path caps here.
Outside of the signal path I use mostly Panasonic FC except for the PSU where I use UCC KYB and Panasonic FM. These have high ripple rating for their phisical size, are 105° rated, low ESR and are long life. You can gain some extra ripple current rating by going up in voltage a step or 2. The higher voltage caps will also often have a lower ESR.
Considering the large PSU filter caps. I can't tell by the low quality lay-out scans if the 22000µF/75v caps have 2 leads or 4 leads (2 of which will be dummy for stability). Most (perhaps all) of the AX amps that I've worked on so far have 4 pins, with the +/- leads on 22mm centers. You need to check this before choosing caps for these positions. Also I need to know the diameter and height of the existing caps and if there is room for larger dia or taller caps.
In general, for almost all caps in any amp I've been using at least 1 voltage step higher than called for
where they fit. For instance 25v for where 16v is called for. One place where this almost never works is for the 2x 2200µF/6.3v caps in the phono section. For these 2 caps there is almost never room for a larger cap and I usually use Nichicon FG in 6.3v. Going up a step in voltage means that the caps are a little more expensive but in practice that is offset somewhat by being able to buy a single higher voltage cap for several different positions and get a volume discount.
One of the reasons that I've gone away from using Nichicon FG is that I've noticed too often that they measure low in µF even when new. This happens with the Panasonic FC & FM also but not as often. And the FC/FM caps are 105° rated and high hour rated. I think that they are a pretty darn good value for a reasonable cost. But if you are on a really tight budget and buying mostly FG is more cost effective for you the FG's are certainly a quality useful cap. You have to look at Mouser (or where you are buying from) and make a comparison. Of course you did say that you want to get the best out of the amp.
Cheers,
James
edit: If you have an original SM or better scans than HiFi Engine please double check the cap position numbers. Some of them were very difficult to read.